From e964385bc1f8588bbaa80555fc34a38d8d8dbe84 Mon Sep 17 00:00:00 2001
From: Ben Weissmann <benweissmann@gmail.com>
Date: Wed, 4 Sep 2019 17:51:16 -0400
Subject: [PATCH] Add types for multivariate-normal (#37989)

* Add multivariate-normal

* Update metadata

* Remove patch version

* Improve tests and immutability annotations

* Allow readonly array in mutators
---
 types/multivariate-normal/index.d.ts          | 17 +++++++++
 .../multivariate-normal-tests.ts              | 35 +++++++++++++++++++
 types/multivariate-normal/tsconfig.json       | 23 ++++++++++++
 types/multivariate-normal/tslint.json         |  1 +
 4 files changed, 76 insertions(+)
 create mode 100644 types/multivariate-normal/index.d.ts
 create mode 100644 types/multivariate-normal/multivariate-normal-tests.ts
 create mode 100644 types/multivariate-normal/tsconfig.json
 create mode 100644 types/multivariate-normal/tslint.json

diff --git a/types/multivariate-normal/index.d.ts b/types/multivariate-normal/index.d.ts
new file mode 100644
index 0000000000..80ab120ef1
--- /dev/null
+++ b/types/multivariate-normal/index.d.ts
@@ -0,0 +1,17 @@
+// Type definitions for multivariate-normal 0.1
+// Project: https://github.com/tulip/multivariate-normal-js#readme
+// Definitions by: Ben Weissmann <https://github.com/benweissmann>
+// Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
+
+export interface Distribution {
+  sample(): number[];
+  getMean(): ReadonlyArray<number>;
+  setMean(newMean: ReadonlyArray<number>): Distribution;
+  getCov(): ReadonlyArray<ReadonlyArray<number>>;
+  setCov(newCov: ReadonlyArray<ReadonlyArray<number>>): Distribution;
+}
+
+export default function MultivariateNormal(
+  mean: ReadonlyArray<number>,
+  cov: ReadonlyArray<ReadonlyArray<number>>,
+): Distribution;
diff --git a/types/multivariate-normal/multivariate-normal-tests.ts b/types/multivariate-normal/multivariate-normal-tests.ts
new file mode 100644
index 0000000000..6c1136049d
--- /dev/null
+++ b/types/multivariate-normal/multivariate-normal-tests.ts
@@ -0,0 +1,35 @@
+import MultivariateNormal from 'multivariate-normal';
+
+// Test constructing using mutable and literal arrays
+const mutArray: number[] = [1, 2, 3];
+const dist = MultivariateNormal(mutArray, [[0, 0, 1], [0, 1, 0], [1, 0, 0]]);
+
+// Test methods for creating a new distribution from an existing one using
+// mutable and literal arrays
+const mutArray2: number[] = [4, 5, 6];
+const newDist = dist.setMean(mutArray2).setCov([[0, 0, 1], [0, 1, 0], [1, 0, 0]]);
+
+// Test accessors
+const newMean: ReadonlyArray<number> = newDist.getMean();
+const newCov: ReadonlyArray<ReadonlyArray<number>> = newDist.getCov();
+
+// Mean and covariance are immutable
+
+// $ExpectError
+newDist.getMean()[0] = 10;
+
+// $ExpectError
+newDist.getCov()[0] = [1, 2, 3];
+
+// $ExpectError
+newDist.getCov()[0][0] = 10;
+
+// Samples are mutable
+const sample: number[] = newDist.sample();
+sample[0] = 123;
+
+// Check that we can pass immutable arrays into the constructor or mutators
+MultivariateNormal(newDist.getMean(), newDist.getCov());
+
+newDist.setCov(dist.getCov());
+newDist.setMean(dist.getMean());
diff --git a/types/multivariate-normal/tsconfig.json b/types/multivariate-normal/tsconfig.json
new file mode 100644
index 0000000000..20334dba61
--- /dev/null
+++ b/types/multivariate-normal/tsconfig.json
@@ -0,0 +1,23 @@
+{
+    "compilerOptions": {
+        "module": "commonjs",
+        "lib": [
+            "es6"
+        ],
+        "noImplicitAny": true,
+        "noImplicitThis": true,
+        "strictFunctionTypes": true,
+        "strictNullChecks": true,
+        "baseUrl": "../",
+        "typeRoots": [
+            "../"
+        ],
+        "types": [],
+        "noEmit": true,
+        "forceConsistentCasingInFileNames": true
+    },
+    "files": [
+        "index.d.ts",
+        "multivariate-normal-tests.ts"
+    ]
+}
diff --git a/types/multivariate-normal/tslint.json b/types/multivariate-normal/tslint.json
new file mode 100644
index 0000000000..3db14f85ea
--- /dev/null
+++ b/types/multivariate-normal/tslint.json
@@ -0,0 +1 @@
+{ "extends": "dtslint/dt.json" }